Apart from the rocks not leaving any way (as already mentioned), I noticed that sometimes the hitboxes of the rocks are larger than they look, which is a bit frustrating and makes it impossible to thread the needle in small passages.
Apart from that, I really liked the game, and although the music is not original, it fits the game well. If you decide to develop this game further, I would suggest adding difficulty settings or sliders for rock- and water density or something to that effect.